wimlib.net Git - wimlib/blob - src/modify.c

   1 /*
   2  * modify.c
   3  *
   4  * Support for modifying WIM files with image-level operations (delete an image,
   5  * add an image, export an imagex from one WIM to another.)  There is nothing
   6  * here that lets you change individual files in the WIM; for that you will need
   7  * to look at the filesystem implementation in mount.c.
   8  */
   9
  10 /*
  11  * Copyright (C) 2012 Eric Biggers
  12  *
  13  * This file is part of wimlib, a library for working with WIM files.
  14  *
  15  * wimlib is free software; you can redistribute it and/or modify it under the
  16  * terms of the GNU Lesser General Public License as published by the Free
  17  * Software Foundation; either version 2.1 of the License, or (at your option)
  18  * any later version.
  19  *
  20  * wimlib is distributed in the hope that it will be useful, but WITHOUT ANY
  21  * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
  22  * A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
  23  * details.
  24  *
  25  * You should have received a copy of the GNU Lesser General Public License
  26  * along with wimlib; if not, see http://www.gnu.org/licenses/.
  27  */
  28
  29 #include "wimlib_internal.h"
  30 #include "util.h"
  31 #include "sha1.h"
  32 #include "dentry.h"
  33 #include "xml.h"
  34 #include "lookup_table.h"
  35 #include <sys/stat.h>
  36 #include <dirent.h>
  37 #include <string.h>
  38 #include <errno.h>
  39 #include <unistd.h>
  40
  41 /** Private flag: Used to mark that we currently adding the root directory of
  42  * the WIM. */
  43 #define WIMLIB_ADD_IMAGE_FLAG_ROOT 0x80000000
  44
  45 void destroy_image_metadata(struct image_metadata *imd,struct lookup_table *lt)
  46 {
  47         free_dentry_tree(imd->root_dentry, lt);
  48         free_security_data(imd->security_data);
  49         free_link_group_table(imd->lgt);
  50
  51         /* Get rid of the lookup table entry for this image's metadata resource
  52          * */
  53         if (lt)
  54                 lookup_table_remove(lt, imd->metadata_lte);
  55 }
  56
  57 /*
  58  * Recursively builds a dentry tree from a directory tree on disk, outside the
  59  * WIM file.
  60  *
  61  * @root:  A dentry that has already been created for the root of the dentry
  62  *         tree.
  63  * @root_disk_path:  The path to the root of the tree on disk.
  64  * @lookup_table: The lookup table for the WIM file.  For each file added to the
  65  *              dentry tree being built, an entry is added to the lookup table,
  66  *              unless an identical file is already in the lookup table.  These
  67  *              lookup table entries that are added point to the file on disk.
  68  *
  69  * @return:     0 on success, nonzero on failure.  It is a failure if any of
  70  *              the files cannot be `stat'ed, or if any of the needed
  71  *              directories cannot be opened or read.  Failure to add the files
  72  *              to the WIM may still occur later when trying to actually read
  73  *              the regular files in the tree into the WIM as file resources.
  74  */
  75 static int build_dentry_tree(struct dentry *root, const char *root_disk_path,
  76                              struct lookup_table *lookup_table,
  77                              struct wim_security_data *sd,
  78                              int add_flags,
  79                              void *extra_arg)
  80 {
  81         DEBUG("%s", root_disk_path);
  82         struct stat root_stbuf;
  83         int ret = 0;
  84         int (*stat_fn)(const char *restrict, struct stat *restrict);
  85
  86         if (add_flags & WIMLIB_ADD_IMAGE_FLAG_DEREFERENCE)
  87                 stat_fn = stat;
  88         else
  89                 stat_fn = lstat;
  90
  91         if (add_flags & WIMLIB_ADD_IMAGE_FLAG_VERBOSE)
  92                 printf("Scanning `%s'\n", root_disk_path);
  93
  94
  95         ret = (*stat_fn)(root_disk_path, &root_stbuf);
  96         if (ret != 0) {
  97                 ERROR_WITH_ERRNO("Failed to stat `%s'", root_disk_path);
  98                 return WIMLIB_ERR_STAT;
  99         }
 100
 101         if ((add_flags & WIMLIB_ADD_IMAGE_FLAG_ROOT) &&
 102               !S_ISDIR(root_stbuf.st_mode)) {
 103                 ERROR("`%s' is not a directory", root_disk_path);
 104                 return WIMLIB_ERR_NOTDIR;
 105         }
 106         if (!S_ISREG(root_stbuf.st_mode) && !S_ISDIR(root_stbuf.st_mode)
 107             && !S_ISLNK(root_stbuf.st_mode)) {
 108                 ERROR("`%s' is not a regular file, directory, or symbolic link.");
 109                 return WIMLIB_ERR_SPECIAL_FILE;
 110         }
 111         stbuf_to_dentry(&root_stbuf, root);
 112         add_flags &= ~WIMLIB_ADD_IMAGE_FLAG_ROOT;
 113         root->resolved = true;
 114
 115         if (dentry_is_directory(root)) {
 116                 /* Open the directory on disk */
 117                 DIR *dir;
 118                 struct dirent *p;
 119                 struct dentry *child;
 120
 121                 dir = opendir(root_disk_path);
 122                 if (!dir) {
 123                         ERROR_WITH_ERRNO("Failed to open the directory `%s'",
 124                                          root_disk_path);
 125                         return WIMLIB_ERR_OPEN;
 126                 }
 127
 128                 /* Buffer for names of files in directory. */
 129                 size_t len = strlen(root_disk_path);
 130                 char name[len + 1 + FILENAME_MAX + 1];
 131                 memcpy(name, root_disk_path, len);
 132                 name[len] = '/';
 133
 134                 /* Create a dentry for each entry in the directory on disk, and recurse
 135                  * to any subdirectories. */
 136                 while ((p = readdir(dir)) != NULL) {
 137                         if (p->d_name[0] == '.' && (p->d_name[1] == '\0'
 138                               || (p->d_name[1] == '.' && p->d_name[2] == '\0')))
 139                                         continue;
 140                         strcpy(name + len + 1, p->d_name);
 141                         child = new_dentry(p->d_name);
 142                         if (!child)
 143                                 return WIMLIB_ERR_NOMEM;
 144                         ret = build_dentry_tree(child, name, lookup_table,
 145                                                 sd, add_flags, extra_arg);
 146                         link_dentry(child, root);
 147                         if (ret != 0)
 148                                 break;
 149                 }
 150                 closedir(dir);
 151         } else if (dentry_is_symlink(root)) {
 152                 /* Archiving a symbolic link */
 153                 size_t symlink_buf_len;
 154                 char deref_name_buf[4096];
 155                 ssize_t deref_name_len;
 156
 157                 deref_name_len = readlink(root_disk_path, deref_name_buf,
 158                                           sizeof(deref_name_buf) - 1);
 159                 if (deref_name_len == -1) {
 160                         ERROR_WITH_ERRNO("Failed to read target of "
 161                                          "symbolic link `%s'", root_disk_path);
 162                         return WIMLIB_ERR_READLINK;
 163                 }
 164                 deref_name_buf[deref_name_len] = '\0';
 165                 DEBUG("Read symlink `%s'", deref_name_buf);
 166                 ret = dentry_set_symlink(root, deref_name_buf,
 167                                          lookup_table, NULL);
 168         } else {
 169                 /* Regular file */
 170                 struct lookup_table_entry *lte;
 171                 u8 hash[SHA1_HASH_SIZE];
 172
 173                 /* For each regular file, we must check to see if the file is in
 174                  * the lookup table already; if it is, we increment its refcnt;
 175                  * otherwise, we create a new lookup table entry and insert it.
 176                  * */
 177                 ret = sha1sum(root_disk_path, hash);
 178                 if (ret != 0)
 179                         return ret;
 180
 181                 lte = __lookup_resource(lookup_table, hash);
 182                 if (lte) {
 183                         lte->refcnt++;
 184                         DEBUG("Add lte reference %u for `%s'", lte->refcnt,
 185                               root_disk_path);
 186                 } else {
 187                         char *file_on_disk = STRDUP(root_disk_path);
 188                         if (!file_on_disk) {
 189                                 ERROR("Failed to allocate memory for file path");
 190                                 return WIMLIB_ERR_NOMEM;
 191                         }
 192                         lte = new_lookup_table_entry();
 193                         if (!lte) {
 194                                 FREE(file_on_disk);
 195                                 return WIMLIB_ERR_NOMEM;
 196                         }
 197                         lte->file_on_disk = file_on_disk;
 198                         lte->resource_location = RESOURCE_IN_FILE_ON_DISK;
 199                         lte->resource_entry.original_size = root_stbuf.st_size;
 200                         lte->resource_entry.size = root_stbuf.st_size;
 201                         copy_hash(lte->hash, hash);
 202                         lookup_table_insert(lookup_table, lte);
 203                 }
 204                 root->lte = lte;
 205         }
 206         return ret;
 207 }
 208
 209 struct wim_pair {
 210         WIMStruct *src_wim;
 211         WIMStruct *dest_wim;
 212 };
 213
 214 /*
 215  * This function takes in a dentry that was previously located only in image(s)
 216  * in @src_wim, but now is being added to @dest_wim. If there is in fact already a
 217  * lookup table entry for this file in the lookup table of the destination WIM
 218  * file, we simply increment its reference count.  Otherwise, a new lookup table
 219  * entry is created that references the location of the file resource in the
 220  * source WIM file through the other_wim_fp field of the lookup table entry.
 221  */
 222 static int add_lte_to_dest_wim(struct dentry *dentry, void *arg)
 223 {
 224         WIMStruct *src_wim, *dest_wim;
 225
 226         src_wim = ((struct wim_pair*)arg)->src_wim;
 227         dest_wim = ((struct wim_pair*)arg)->dest_wim;
 228
 229         wimlib_assert(!dentry->resolved);
 230
 231         for (unsigned i = 0; i < (unsigned)dentry->num_ads + 1; i++) {
 232                 struct lookup_table_entry *src_lte, *dest_lte;
 233                 src_lte = dentry_stream_lte_unresolved(dentry, i,
 234                                                        src_wim->lookup_table);
 235                 if (!src_lte)
 236                         continue;
 237                 dest_lte = dentry_stream_lte_unresolved(dentry, i,
 238                                                         dest_wim->lookup_table);
 239                 if (dest_lte) {
 240                         dest_lte->refcnt++;
 241                 } else {
 242                         dest_lte = new_lookup_table_entry();
 243                         if (!dest_lte)
 244                                 return WIMLIB_ERR_NOMEM;
 245                         dest_lte->resource_location = RESOURCE_IN_WIM;
 246                         dest_lte->wim = src_wim;
 247                         memcpy(&dest_lte->resource_entry,
 248                                &src_lte->resource_entry,
 249                                sizeof(struct resource_entry));
 250                         copy_hash(dest_lte->hash,
 251                                   dentry_stream_hash_unresolved(dentry, i));
 252                         lookup_table_insert(dest_wim->lookup_table, dest_lte);
 253                 }
 254         }
 255         return 0;
 256 }
 257
 258 /*
 259  * Adds an image (given by its dentry tree) to the image metadata array of a WIM
 260  * file, adds an entry to the lookup table for the image metadata, updates the
 261  * image count in the header, and selects the new image.
 262  *
 263  * Does not update the XML data.
 264  *
 265  * @w:            The WIMStruct for the WIM file.
 266  * @root_dentry:  The root of the directory tree for the image.
 267  */
 268 static int add_new_dentry_tree(WIMStruct *w, struct dentry *root_dentry,
 269                                struct wim_security_data *sd)
 270 {
 271         struct lookup_table_entry *metadata_lte;
 272         struct image_metadata *imd;
 273         struct image_metadata *new_imd;
 274         struct link_group_table *lgt;
 275
 276         DEBUG("Reallocating image metadata array for image_count = %u",
 277               w->hdr.image_count + 1);
 278         imd = CALLOC((w->hdr.image_count + 1), sizeof(struct image_metadata));
 279
 280         if (!imd) {
 281                 ERROR("Failed to allocate memory for new image metadata array");
 282                 return WIMLIB_ERR_NOMEM;
 283         }
 284
 285         memcpy(imd, w->image_metadata,
 286                w->hdr.image_count * sizeof(struct image_metadata));
 287
 288         metadata_lte = new_lookup_table_entry();
 289         if (!metadata_lte)
 290                 goto out_free_imd;
 291
 292         lgt = new_link_group_table(9001);
 293         if (!lgt)
 294                 goto out_free_security_data;
 295
 296         metadata_lte->resource_entry.flags = WIM_RESHDR_FLAG_METADATA;
 297         random_hash(metadata_lte->hash);
 298         lookup_table_insert(w->lookup_table, metadata_lte);
 299
 300         new_imd = &imd[w->hdr.image_count];
 301
 302         new_imd->root_dentry    = root_dentry;
 303         new_imd->metadata_lte   = metadata_lte;
 304         new_imd->security_data  = sd;
 305         new_imd->lgt            = lgt;
 306         new_imd->modified       = true;
 307
 308         FREE(w->image_metadata);
 309         w->image_metadata       = imd;
 310         w->hdr.image_count++;
 311
 312         /* Change the current image to the new one. */
 313         return wimlib_select_image(w, w->hdr.image_count);
 314 out_free_security_data:
 315         FREE(sd);
 316 out_free_metadata_lte:
 317         FREE(metadata_lte);
 318 out_free_imd:
 319         FREE(imd);
 320         return WIMLIB_ERR_NOMEM;
 321
 322 }
 323
 324 /*
 325  * Copies an image, or all the images, from a WIM file, into another WIM file.
 326  */
 327 WIMLIBAPI int wimlib_export_image(WIMStruct *src_wim,
 328                                   int src_image,
 329                                   WIMStruct *dest_wim,
 330                                   const char *dest_name,
 331                                   const char *dest_description,
 332                                   int flags)
 333 {
 334         int i;
 335         int ret;
 336         struct dentry *root;
 337         struct wim_pair wims;
 338         struct wim_security_data *sd;
 339
 340         if (src_image == WIM_ALL_IMAGES) {
 341                 if (src_wim->hdr.image_count > 1) {
 342
 343                         /* multi-image export. */
 344
 345                         if ((flags & WIMLIB_EXPORT_FLAG_BOOT) &&
 346                               (src_wim->hdr.boot_idx == 0))
 347                         {
 348                                 /* Specifying the boot flag on a multi-image
 349                                  * source WIM makes the boot index default to
 350                                  * the bootable image in the source WIM.  It is
 351                                  * an error if there is no such bootable image.
 352                                  * */
 353                                 ERROR("Cannot specify `boot' flag when "
 354                                       "exporting multiple images from a WIM "
 355                                       "with no bootable images");
 356                                 return WIMLIB_ERR_INVALID_PARAM;
 357                         }
 358                         if (dest_name || dest_description) {
 359                                 ERROR("Image name or image description was "
 360                                       "specified, but we are exporting "
 361                                       "multiple images");
 362                                 return WIMLIB_ERR_INVALID_PARAM;
 363                         }
 364                         for (i = 1; i <= src_wim->hdr.image_count; i++) {
 365                                 int export_flags = flags;
 366
 367                                 if (i != src_wim->hdr.boot_idx)
 368                                         export_flags &= ~WIMLIB_EXPORT_FLAG_BOOT;
 369
 370                                 ret = wimlib_export_image(src_wim, i, dest_wim,
 371                                                           NULL,
 372                                                           dest_description,
 373                                                           export_flags);
 374                                 if (ret != 0)
 375                                         return ret;
 376                         }
 377                         return 0;
 378                 } else {
 379                         src_image = 1;
 380                 }
 381         }
 382
 383         ret = wimlib_select_image(src_wim, src_image);
 384         if (ret != 0) {
 385                 ERROR("Could not select image %d from the WIM `%s' "
 386                       "to export it", src_image, src_wim->filename);
 387                 return ret;
 388         }
 389
 390         if (!dest_name) {
 391                 dest_name = wimlib_get_image_name(src_wim, src_image);
 392                 DEBUG("Using name `%s' for source image %d",
 393                       dest_name, src_image);
 394         }
 395
 396         DEBUG("Exporting image %d from `%s'", src_image, src_wim->filename);
 397
 398         if (wimlib_image_name_in_use(dest_wim, dest_name)) {
 399                 ERROR("There is already an image named `%s' in the "
 400                       "destination WIM", dest_name);
 401                 return WIMLIB_ERR_IMAGE_NAME_COLLISION;
 402         }
 403
 404
 405         /* Cleaning up here on failure would be hard.  For example, we could
 406          * fail to allocate memory in add_lte_to_dest_wim(),
 407          * leaving the lookup table entries in the destination WIM in an
 408          * inconsistent state.  Until these issues can be resolved,
 409          * wimlib_export_image() is documented as leaving dest_wim is an
 410          * indeterminate state.  */
 411         root = wim_root_dentry(src_wim);
 412         sd = wim_security_data(src_wim);
 413         for_dentry_in_tree(root, increment_dentry_refcnt, NULL);
 414         wims.src_wim = src_wim;
 415         wims.dest_wim = dest_wim;
 416         ret = for_dentry_in_tree(root, add_lte_to_dest_wim, &wims);
 417         if (ret != 0)
 418                 return ret;
 419         ret = add_new_dentry_tree(dest_wim, root, sd);
 420         if (ret != 0)
 421                 return ret;
 422         sd->refcnt++;
 423
 424         if (flags & WIMLIB_EXPORT_FLAG_BOOT) {
 425                 DEBUG("Setting boot_idx to %d", dest_wim->hdr.image_count);
 426                 dest_wim->hdr.boot_idx = dest_wim->hdr.image_count;
 427         }
 428
 429         return xml_export_image(src_wim->wim_info, src_image, &dest_wim->wim_info,
 430                                 dest_name, dest_description);
 431 }
 432
 433 /*
 434  * Deletes an image from the WIM.
 435  */
 436 WIMLIBAPI int wimlib_delete_image(WIMStruct *w, int image)
 437 {
 438         int num_images;
 439         int i;
 440         int ret;
 441
 442         if (image == WIM_ALL_IMAGES) {
 443                 num_images = w->hdr.image_count;
 444                 for (i = 1; i <= num_images; i++) {
 445                         /* Always delete the first image, since by the end
 446                          * there won't be any more than that!  */
 447                         ret = wimlib_delete_image(w, 1);
 448                         if (ret != 0)
 449                                 return ret;
 450                 }
 451                 return 0;
 452         }
 453
 454         DEBUG("Deleting image %d", image);
 455
 456         /* Even if the dentry tree is not allocated, we must select it (and
 457          * therefore allocate it) so that we can decrement the reference counts
 458          * in the lookup table.  */
 459         ret = wimlib_select_image(w, image);
 460         if (ret != 0)
 461                 return ret;
 462
 463         /* Free the dentry tree, any lookup table entries that have their
 464          * refcnt decremented to 0, and the security data. */
 465         destroy_image_metadata(wim_get_current_image_metadata(w),
 466                                w->lookup_table);
 467
 468         /* Get rid of the empty slot in the image metadata array. */
 469         memmove(&w->image_metadata[image - 1], &w->image_metadata[image],
 470                 (w->hdr.image_count - image) * sizeof(struct image_metadata));
 471
 472         /* Decrement the image count. */
 473         if (--w->hdr.image_count == 0) {
 474                 FREE(w->image_metadata);
 475                 w->image_metadata = NULL;
 476         }
 477
 478         /* Fix the boot index. */
 479         if (w->hdr.boot_idx == image)
 480                 w->hdr.boot_idx = 0;
 481         else if (w->hdr.boot_idx > image)
 482                 w->hdr.boot_idx--;
 483
 484         w->current_image = WIM_NO_IMAGE;
 485
 486         /* Remove the image from the XML information. */
 487         xml_delete_image(&w->wim_info, image);
 488         return 0;
 489 }
 490
 491 int do_add_image(WIMStruct *w, const char *dir, const char *name,
 492                  const char *description, const char *flags_element,
 493                  int flags,
 494                  int (*capture_tree)(struct dentry *, const char *,
 495                                      struct lookup_table *,
 496                                      struct wim_security_data *, int, void *),
 497                  void *extra_arg)
 498 {
 499         struct dentry *root_dentry;
 500         struct image_metadata *imd;
 501         struct wim_security_data *sd;
 502         int ret;
 503
 504         DEBUG("Adding dentry tree from dir `%s'.", dir);
 505
 506         if (!name || !*name) {
 507                 ERROR("Must specify a non-empty string for the image name");
 508                 return WIMLIB_ERR_INVALID_PARAM;
 509         }
 510         if (!dir) {
 511                 ERROR("Must specify the name of a directory");
 512                 return WIMLIB_ERR_INVALID_PARAM;
 513         }
 514
 515         if (wimlib_image_name_in_use(w, name)) {
 516                 ERROR("There is already an image named \"%s\" in `%s'",
 517                       name, w->filename);
 518                 return WIMLIB_ERR_IMAGE_NAME_COLLISION;
 519         }
 520
 521         DEBUG("Creating root dentry.");
 522
 523         root_dentry = new_dentry("");
 524         if (!root_dentry)
 525                 return WIMLIB_ERR_NOMEM;
 526
 527
 528         sd = CALLOC(1, sizeof(struct wim_security_data));
 529         if (!sd)
 530                 goto out_free_dentry_tree;
 531         sd->total_length = 8;
 532         sd->refcnt = 1;
 533
 534         DEBUG("Building dentry tree.");
 535         ret = (*capture_tree)(root_dentry, dir, w->lookup_table, sd,
 536                               flags | WIMLIB_ADD_IMAGE_FLAG_ROOT,
 537                               extra_arg);
 538
 539         if (ret != 0) {
 540                 ERROR("Failed to build dentry tree for `%s'", dir);
 541                 goto out_free_sd;
 542         }
 543
 544         DEBUG("Calculating full paths of dentries.");
 545         ret = for_dentry_in_tree(root_dentry, calculate_dentry_full_path, NULL);
 546         if (ret != 0)
 547                 goto out_free_sd;
 548
 549         ret = add_new_dentry_tree(w, root_dentry, sd);
 550         if (ret != 0)
 551                 goto out_free_sd;
 552
 553         DEBUG("Inserting dentries into hard link group table");
 554         ret = for_dentry_in_tree(root_dentry, link_group_table_insert,
 555                                  w->image_metadata[w->hdr.image_count - 1].lgt);
 556         if (ret != 0)
 557                 goto out_destroy_imd;
 558         DEBUG("Assigning hard link groups");
 559         assign_link_groups(w->image_metadata[w->hdr.image_count - 1].lgt);
 560
 561         if (flags & WIMLIB_ADD_IMAGE_FLAG_BOOT)
 562                 wimlib_set_boot_idx(w, w->hdr.image_count);
 563
 564         ret = xml_add_image(w, root_dentry, name, description, flags_element);
 565         if (ret != 0)
 566                 goto out_destroy_imd;
 567
 568         return 0;
 569 out_destroy_imd:
 570         destroy_image_metadata(&w->image_metadata[w->hdr.image_count - 1],
 571                                w->lookup_table);
 572         w->hdr.image_count--;
 573         return ret;
 574 out_free_sd:
 575         free_security_data(sd);
 576 out_free_dentry_tree:
 577         free_dentry_tree(root_dentry, w->lookup_table);
 578         return ret;
 579 }
 580
 581 /*
 582  * Adds an image to a WIM file from a directory tree on disk.
 583  */
 584 WIMLIBAPI int wimlib_add_image(WIMStruct *w, const char *dir,
 585                                const char *name, const char *description,
 586                                const char *flags_element, int flags)
 587 {
 588         return do_add_image(w, dir, name, description, flags_element, flags,
 589                             build_dentry_tree, NULL);
 590 }